Having performed an extensive literature review of studies comparing treatment entities for perforated non-faeculant diverticulitis, sample size calculations reveal that a patient cohort of 100 in each arm will be sufficient to detect a difference in morbidity and mortality between groups (25% versus 10%; two sided significance 5% and a power of 80%). A significance level of 0.05 on the two sided Likelihood ratio test was used and the significance level achieved by this design is 0.04997.